High performance data processing systems require digital memory systems which are capable of storing and providing large amounts of data at very high speeds. For example, graphics controllers which operate in conjunction with a host computer to perform sophisticated image manipulation and rendering functions to generate data for display on a display screen, require memories which are capable of storing and providing the amount of data required of such functions at very high data rates.
Dynamic Random Access Memories (DRAMs) are often used to meet the storage requirements required by high performance systems. DRAMs are typically characterized by a greater storage density per chip when compared to static random access memories (SRAMs). However, DRAMs are also typically characterized by slower access times then SRAMs.
A variety of techniques have been used to increase the bandwidth of digital memory systems employing DRAMs. For example, the memory, and the data paths to and from the memory, may be organized to allow multiple words of data to be retrieved in a single access. Although such a technique provides increased bandwidth, there remains a need for digital memory systems which provide even greater data storage and data throughput than is currently available.